[TowerTalk] Age Old Question

[K8RI]

>
> Tape works well but only use good stuff like Scotch 33+ or Scotch 88,
> which are specified as all-weather tapes and their adhesive will not
> seriously degrade in freezing temperatures.  (Scotch 33+ is 7 mil and
> Scotch 88 is 8.5 mil thick, BTW.)  But there are two precautions to take
> with tape.   1)  If you pull it very tight by stretching it for every wrap 
> AND
> you put on a lot of wraps it can crush the cable with the cumulative force
> of many wraps, as the tape tries to regain its original shape.  But it

I have to disagree here.

After many years up here in the frozen north, 46 as a ham, I no longer use 
the "good stuff" when it comes to tape.  I'ven had the adhesive seperate 
right off the backing for Scotch Brand tape on several occasions.   I go to 
Lowe's or Home Depot and buy the stuff they have in 10 or 12 roll packages. 
Narry a problem yet, but it do get a tad gooey on hot summer days. OTOH I've 
never had it come off.

The other is, I don't believe it's possible to crush the coax on a *smooth* 
surface unless you give it 10 turns or more with one wrap on top on the 
other and each pulled as tight as you can get it. Even then it'd have to be 
small and flexible coax.  Normally to pull it tight enough to damge the coax 
the tape would break first. Yes, I can see where it *might* on an irregular 
surface such as over a tower brace, or a bump in the galvanizing, but 
otherwize I've never even seen a dent or compression show in the jacket. 
After this many years, it the mistake can be made I've probably made 
it...several times over.

> takes a lot of layers and if you use good tape, which is expensive,
> you are less likely to use that much of it.   2)  On the last turn or two
> of tape you do not want to pull it very tight so that it won't "flag" on

So, I've had a few flags?  What few there have been were no problem except 
for looks. and I'd rather have a flag than the adhesive come off in the cold 
weather.  You pull the tape apart, let it relax for a few seconds tand then 
smooth it down over the previous wrap. It rarely comes loose.


> you, a problem which is exacerbated by pulling the tape to break the
> roll loose from the wrap.  You always want to CUT the tape when you
> stop the wrap.   Good scissors are best because even using a knife
> can add some stretch to the tape as you tension the tape enough to

I put lots of tension on every wrap and make the wrap 2 to 3" wide. It 
really doesn't take that much more tape.  It gives a much beter grip while 
exerting far less pressure on the cable.

> cut it.  Tape does provide a bit of vertical support if enough layers are

If the tape is wound to form a band it will provide a lot of vertical 
support. It does take more tape but not much.

> used, but it is difficult to reuse the tape again if you want to add 
> cables
> in the future.

I don't even reuse conax connectors, except for the big expensive ones.

>
> Plastic cable ties are a possible choice but there are THREE types.
> Ones that are not UV resistant and that will promptly degrade in a
> season or two of sunshine.  There are ones (usually black) that are
> UV resistant and that will last many seasons in the sunshine, but probably

I tried the expensive, name brand ones from the local electrical 
distributor.  They lasted about 2 years.

> not "forever".  And then there are ones that CLAIM to be UV resistant
> but are not very good and will fail in a couple of seasons.  It is 
> difficult
> to tell the second group from the third group and about all you can do is
> to use QUALITY UV-resistant nylon ties -- the bargain ones that are

Nylon is not UV resistant.

I think you will find the truly UV resistant are a compound that is not 
Nylon, but I've not had good luck with even those expensive, name brand one 
lasting more than a couple of years. Actually they lasted about 5, but when 
I went up to check them over time I found they had little strength left 
after 2 years.  You could easily break them with two fingers. Possibly there 
are truly better ones out there, but I have yet to find them. I have found a 
lot that aren't as good though.

 73

Roger (K8RI)